Thin film core of Co-Fe-B alloy

ABSTRACT

A thin film magnetic read/write head has a cobalt iron boron core. Cobalt, iron and boron are included in the electroplating bath used to form the pole pieces of the thin film magnetic head. Following exposure to a rotating magnetic field, the pole pieces have high saturation magnetization, low coercivity, low anisotropy and large permeability.

This is a continuation of application Ser. No. 07/425,735 filed on Oct.20, 1989, abandoned as of the date of this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention.

The present invention relates to a thin film magnetic head having acobalt-iron-boron core.

2. Description of the Prior Art.

Thin film magnetic read/write heads are used for magnetically readingand writing information on a magnetic storage medium such as a magneticdisk or magnetic tape. As data storage requirements have risen, it hasbecome increasingly desirable to provide high levels of informationstorage densities on the magnetic storage medium. Increased storagedensities require magnetic read/write heads which provide a strongwriting field in relation to the applied writing current and highpermeability for large signal output. This may be achieved by making theanisotropy field (H_(k)) as small as possible thereby increasing thepermeability (μ). Increased μ also results in increased sensitivity wheninformation is read from the magnetic storage medium. Smaller coercivity(H_(c)) in a read/write magnetic head is also desirable.

U.S. Pat. No. 4,661,216 relates to a cobalt-nickel-iron electroplatingcomposition bath used to produce a thin film head having a saturationmagnetization (4πM_(s)) of about 14 K gauss, a coercivity (H_(c)) ofabout 2 Oersteds, an anisotropy field (H_(k)) of about 13 Oersteds and apermeability (μ) of about 1000.

It would be desireable to produce a thin film magnetic head having a yetsmaller anisotropic field (H_(k)) coercivity (H_(c)), while maintaininga large saturated magnetization (M_(s) or 4πM_(s)), and increasing thepermeability (μ).

SUMMARY OF THE INVENTION

The present invention provides a thin film magnetic head having areduced coercivity H_(c) and anisotropy field H_(k) while maintaining alarge saturation magnetization (M_(s) or 4πM_(s) ). An increasedpermeability (μ) is also provided.

The improved thin film head core of the present invention uses a corecomprising cobalt-iron with the addition of boron in the alloy. Thisimproved core may be deposited through electrodeposition techniques. Theanisotropy field, H_(k), may be reduced if an alternating magnetic fieldis applied to the core during the electroplating process. Alternatively,the core may be subjected to rotating field annealing to lower theanisotropy field, H_(k). The resulting cobalt iron boron core has asaturation magnetization (4πM_(s) ) of about 19 K gauss, H_(c) of about1.0 Oersteds, H_(k) of about 7 Oersteds and a permeability (μ) of about2500.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a bar magnet.

FIG. 2 is graph of magnetization versus applied magnetic field in theeasy axis of a magnetic material.

FIG. 3 is a graph of magnetization versus applied magnetic field in thehard axis of a magnetic material.

FIG. 4 is a plan view of a thin film magnetic read/write head.

FIG. 5 is a plan view of a thin film magnetic read/write head showing amagnetic domain pattern.

FIG. 6 is a cross sectional view of a thin film magnetic read/writehead.

FIG. 7 is a cross sectional view of the substrate shown in FIG. 6.

FIG. 8 is a cross sectional view of the substrate of FIG. 7 including abase coat layer.

FIG. 9 is a cross sectional view of the structure of FIG. 8 followingdeposition of a portion of the magnetic core material.

FIGS. 10 and 11 are cross sectional views of the structure of FIG. 9following deposition of electrical conductors.

FIG. 12 is a cross sectional view of the structure of FIG. 11 followingdeposition of insulation layers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides a thin film magnetic head having magneticcharacteristics offering improved performance. The magnetic head of thepresent invention is formed with a metal alloy comprising cobalt, ironand boron to improve head performance. A cursory review of magnetics isgiven to explain the performance characteristics of thin film magnetics.FIGS. 1-5 and the following discussion describe the meaning andsignificance of the easy and hard axis, anisotrophy field (H_(k)),permeability (μ), coercivity (H_(c)) and saturation magnetization(4πMs).

Bar magnet 6 is shown in FIG. 1 along with arrows 8 and 10 indicatingthe easy axis and the hard axis respectively of bar magnet 6. The easyaxis refers to the preferred direction of the magnetization vector (M)within a magnetic material in a relaxed state. In a magnet, the easyaxis is parallel with the axis of the poles. The hard axis, on the otherhand, refers to a direction perpendicular to the easy axis, as shown inFIG. 1 by arrow 10. When a magnetizing field H is applied to a magneticmaterial, the magnetization vector M of the material tends to deflect inthe direction of the applied field H. By applying a sufficiently largemagnetization field H in a direction other than the direction of themagnetic material's easy axis, the material's magnetization vector M isdeflected away from its preferred direction in the relaxed state,parallel to the easy axis. The deflected magnetization vector M is shownas M (Resultant) in FIG. 1.

When an alternating magnetic field H is applied to a magnetic materialalong that material's easy axis, a graph of magnetization M versusapplied magnetic field H forms a hysteresis loop as shown in FIG. 2. Themagnetization M is shown as 4πM in units of Gauss. H, the appliedmagnetic field, is shown in units of Oersteds.

Starting from the point labelled P1 in FIG. 2, as a magnetic field H (inthe easy axis direction) is applied to the magnetic material, themagnetization M follows the dashed line to the point labelled P2 in FIG.2. Once the material reaches the point P2 in FIG. 2, the material issaturated and any additional magnetic field H applied to the materialresults in no further increase in the material's magnetization. Furtherincrease of applied H moves the plot to P3 in FIG. 2. This saturationmagnetization value is 4πM_(s) in FIG. 2.

As the level of the applied magnetic field H is decreased and thedirection of its vector is reversed, the hysteresis graph for thematerial follows the path from point P3 through P2 and to the pointlabelled P4 in FIG. 2. The material's magnetization does not change fromits saturated value of 4πM_(s). A further increase of the appliedmagnetic field H in the reverse direction causes the magnetization Mwithin the magnetic material to begin to decrease following the pathfrom point P4 to the point labelled P5 passing through the pointlabelled -H_(c) on the hysteresis loop shown in FIG. 2. Once point P5 inFIG. 2 is reached, further increase of the magnetic field H (in thereverse direction) results in no further increase in the magnetizationof the material and the material is once again saturated at the valueshown as -4πM_(s) in FIG. 2. Further increase in the strength of theapplied magnetic field H moves the plot from point P5 to the pointlabelled P6 in FIG. 2.

As the applied magnetic field H is increased from its value at point P6through point P5 and zero and to the point labelled P7 in FIG. 2, themagnetization of the material does not change from its saturated valueof -4πM_(s). Additional increase of the magnetic field H causes thematerial's magnetization to follow the path from point P7 to point P2through H_(c) on the hysteresis loop. By continuing to vary the appliedmagnetic field H, the material may be made to repeatedly follow thehysteresis path of FIG. 2.

The points labelled H_(c) and -H_(c) represent the coercive force, orcoercivity of the magnetic material. The area of the hysteresis loopcorresponds to the energy loss during one hysteresis cycle. Hysteresisloss is the energy lost in the form of heat in overcoming the frictionencountered during domain wall motion and domain rotation. In magneticread/write heads, it is desirable to have a large saturationmagnetization and a small H_(c) such that the shape of the hysteresisloop is generally tall and thin. FIG. 3 shows a graph of magnetization Mof a material in 4πM measured in gauss versus applied magnetic field H.In FIG. 3, the vector H has been applied in a direction parallel to thehard axis and perpendicular to the easy axis of a magnetic material.Unlike the graph of FIG. 2, there is no hysteresis loop in the graph ofmagnetization M verses applied magnetic field H along the hard axis.Similar to the graph of FIG. 2, in FIG. 3 H is the applied magneticfield and 4πM is the resultant magnetization vector within the magneticmaterial. With no applied magnetic field H, the magnetization along thehard axis direction is zero. As the value of H is increased in thedirection parallel with the hard axis, the plot of magnetization followsthe line from the point labelled P8 on the graph of FIG. 3 to the pointlabelled P9 in FIG. 3. At point P9, a maximum magnetization value 4πMhas been reached for the material and the material is saturated having amagnetization equal to 4πM_(s). Further increase in the applied magneticfield H results in no further increase in the magnetization of thematerial beyond the 4πM_(s) value, and the plot continues to the pointlabelled P10.

As applied H is reduced through zero and made increasingly negative, themagnetization M of the material decreases from its value at points P9and P10 of 4πM_(s) through zero at point P8 and ultimately reachessaturation again with a value of -4πM_(s) shown at the point labelledP11 in FIG. 3. Further increase in the applied magnetic field (in thereverse direction) beyond the level necessary to reach the point P11results in no corresponding increase in the material's magnetization Mand the plot moves to the point labelled P12 in FIG. 3. The value of theapplied magnetic field H in the hard axis necessary to place themagnetic material in saturation is known as the anisotropic field and islabelled H_(k). The permeability of the material, μ may be expressed as:##EQU1## where M_(s) is the saturated magnetization value for thematerial and H_(k) is the anisotropy of the material. The finalapproximation in Equation 1 may be made because the factor 4πM/H is muchgreater than one. Thus the slope of the graph of FIG. 3 is approximatelyequal to the permeability μ of the magnetic material. The larger that μis for the material, the smaller the applied magnetic field H must be toachieve the same magnetization 4πM. FIG. 3 graphically shows that asH_(k) is decreased the permeability μ for the material will increase asthe slope of the curve in FIG. 3 increases.

FIG. 4 shows thin film head 12 comprising core 13 including upper polepiece 14 and lower pole piece 16. Conductors 18 extend through thin filmhead 12 and are sandwiched between upper pole piece 14 and lower polepiece 16. Upper pole piece 14 includes upper pole tip 20 while lowerpole piece 16 includes lower pole tip 22. A gap 24 is shown as formedbetween upper pole tip 20 and lower pole tip 22. Typically, aluminafills the gap. A magnetic storage medium (not shown) may be placed neargap 24 such that information may be written on or read from the medium.

Also shown in FIG. 4 is an arrow labelled H (Applied) indicating thedirection of the applied magnetic field H and an arrow labelled M(Relaxed) indicating the magnetization M of the thin film head 12 in itsrelaxed state. In operation, a magnetic storage medium such as amagnetic disk or a magnetic tape moves in the region near gap 24 formedbetween upper pole tip 20 and lower pole tip 22. As electrical currentis caused to flow in conductors 18 in the direction indicated, amagnetic field H will be applied to thin film head 12 in the directionshown by the arrow labelled H (Applied) in FIG. 4. This applied magneticfield causes the magnetization M of the material to change directionfrom the direction indicated by the arrow labelled M (Relaxed) to thedirection indicated by the arrow formed by the dashed lined labelled M(Resultant). As the dashed line labelled M (Resultant) is deflected awayfrom the easy axis in a direction toward gap 24 formed between upperpole tip 20 and lower pole tip 22 due to the applied magnetic field Hfrom electrical current passing through conductors 18, upper pole tip 20will become an increasingly strong north pole while lower pole tip 22becomes a south pole. This causes a fringe field to form around gap 24with a magnetic field vector having direction from upper pole tip 20 tolower pole tip 22.

In a similar manner, if the current through conductors 18 were reversedfrom the direction indicated in FIG. 4, upper pole tip 20 would become asouth pole while lower pole tip 22 would become a north pole. This wouldcause a fringe field around gap 24 with a magnetic field in a directionfrom lower pole tip 22 to upper pole tip 20. Thus it is possible bymodulating the flow of the electrical current through conductors 18 tomodulate the magnetization of upper pole tip 20 and lower pole tip 22.Gap 24 between upper pole tip 20 and lower pole tip 22 causes a fringefield to extend beyond the region of gap 24. When a magnetic storagemedium such as a magnetic disk or a magnetic tape is placed in thisfringe field, information may be recorded by impressing a magnetic fieldupon the medium through the fringe field associated with thin film head12. Similarly, magnetization patterns impressed upon a storage mediumpassing through the fringe field region of thin film head 12 cause anelectrical current to flow through conductors 18 such that the storedinformation may be recovered.

FIG. 5 shows thin film head 12 of FIG. 4 including arrows 15A, 15B and15C indicating the direction of the magnetization vectors M in themagnetic domains across upper pole piece 14. Solid arrows 15A in FIG. 5indicate the direction of a magnetic domain's easy axis. Lines 17 inFIG. 5 separating two adjacent magnetic domains indicate the domainwalls. Solid arrows 15A indicate the direction of the magnetizationvector M in the relaxed state of thin film head 12 along its easy axis.Small vertical arrows 15B along the edge of upper pole piece 14 shown inFIG. 5 indicate the magnetization vector in the closure domains. Closuredomains complete the magnetic circuit between adjacent opposing domains.As electrical current is caused to flow through conductors 18 in thedirection indicated, the direction of the magnetization vector M of thedomains in upper pole piece 14 are deflected away from the easy axis asindicated by arrows 15C formed by the dashed lines. It is thisdeflection that causes north and south poles to form at upper pole tip20 and lower pole tip 22, respectively. If H_(k) is made small, therebyincreasing the permeability μ for thin film head 12, the requiredstrength of the applied magnetic field H will be lower to achieve thesame amount of deflection of the material's magnetization M and asmaller electrical current applied through conductors 18 is required

With small H_(c) values, there is little hysteresis that can effect themagnetization rest state. This promotes the lowest energy conditionafter removal of any applied magnetic fields.

It is also desireable to have a magnetic head with a large saturationmagnetization value M_(s) such that it is possible to apply morepowerful magnetic fields to the magnetic storage medium through thefringe field region. A thin film head having a large permeability μ(which is directly proportional to M_(s), see Equation 1 above) willalso have increased sensitivity when information is read back from themagnetic storage medium. Increased sensitivity causes even weak changesin the magnetization of the magnetic storage medium passing through thefringe field region of thin film head 12 to produce relatively largechanges in the electrical current flowing through conductors 18.

With the present invention, thin film read/write heads are producedhaving large saturation magnetization in M_(s), low coercivity H_(c),low anisotropy H_(k) and large permeability μ.

FIG. 6 shows a cross sectional view of a thin film magnetic head 12 ofFIGS. 4 and 5. Thin film head 12 includes base or "flyer" substrate 25and pole pieces or core 13. Flyer substrate 25 may comprise, forexample, ALSIMAG material. Core 13 comprises pole piece 14 and frontlower pole piece 16. Upper pole piece and lower pole piece portions 14and 16 form upper pole tip 20 and lower pole tip 22 between which gap 24is formed. Core 13 also includes rear upper portion 26 and rear lowerportion 28. Upper pole piece and lower pole piece 14 and 16 and rearupper and lower portions 26 and 28 of core 13 meet at center area of"via" 30 (not shown in FIGS. 4 and 5).

Thin film head 12 of FIG. 6 uses two core winding formed by conductors18 and 34. Although only conductors 18 are shown in FIGS. 4 and 5,conductors 18 and 34 are formed in a coil around via 30 of core 13 witha portion of the wrapping being sandwiched between supper pole piece andlower pole piece 14 and 16 of core 13 and a portion of the wrappingsandwiched between rear upper and lower portions 26 and 28 of core 13.Core 13 is separated from substrate 25 by base coat 36. Typically, basecoat 36 is an insulator such as alumina, Al₂ O₃. The area between upperpole piece and lower pole piece 14 and 16 is filled with an insulatingmaterial 38. Typically, insulating material 38 is photoresist. Gap 24between upper pole tip 20 and lower pole tip 22 is filled with alumina,Al₂ O₃. Insulating material 38 is also sandwiched between rear upper andlower portions 26 and 28 of core 13.

During fabrication, multiple heads similar to thin film head 12 may bedeposited across the entire surface of base substrate 25. After thelayers of thin film head 12 are deposited as shown in FIG. 6, basesubstrate 25 (upon which head 12 is formed) is "diced" or sliced intomany individual thin film heads, each carried by a portion of basesubstrate 25, such that upper and lower pole tips 20 and 22 and gap 24are exposed. Gap 24 and pole tips 20 and 22 may then be lapped in adirection generally inward, toward the center of thin film head 12, tothe desired throat dimensions. The lapping process is a grinding processin which the exposed portion of gap 24 is applied to a diamond slurry.Electrical contacts (not shown) are applied to conductors 18 and 34 ofthin film head 12. The completed head may then be attached to some typeof carrying fixture (not shown) for use in reading and writing data on amagnetic storage medium such as a computer disk.

In operation, the magnetic storage medium is placed near upper and lowerpole tips 20 and 22 which form gap 24. During the read operation, thechanging magnetic field due to the moving storage medium impresses amagnetic field upon upper and lower pole tips 20 and 22 formed by upperpole pieces and lower pole pieces 14 and 16 of core 13. This impressedfield is carried around conductors 18 and 34 through upper pole piece14, via 30 and lower pole piece 16 of core 13. This causes an electricalcurrent to be induced in conductors 18 and 34. This electric current isrepresentative of the magnetic field produced by the moving magneticstorage medium. During the write operation, an electric current iscaused to flow in conductor 18 or conductor 34. This results in amagnetic field in core 13 which is applied to the storage medium (notshown) due to the fringing effect at gap 24 formed between upper andlower pole tips 20 and 22 of core 13.

The steps used in fabricating thin film magnetic head 12 of FIGS. 4, 5and 6 are shown individually in FIGS. 7-12. In the cross sectional viewof FIG. 7, base substrate 25 is shown. Base substrate 25 is typicallylarge relative to the dimensions of the thin film magnetic heads and isreferred to as a "wafer." During the manufacturing process, many thinfilm heads such as thin film head 12 typically are fabricated upon basesubstrate 25. For this example, however, only the fabrication of singlethin film magnetic head 12 is shown. Typically, base substrate 25 ismade of an electrically conductive material, such as ALSIMAG.

A base coat layer 36 is deposited across the entire base substrate 25 asshown in FIG. 8. Base coat 36 is a nonconductive material, typicallycomprising alumina, Al₂ O₃. Base coat 36 may be applied using sputteringtechniques.

As shown in FIG. 9, thin film layer 50 of magnetic material is appliedacross the surface using electrodeposition techniques. This process isdescribed below in more detail. Layer 50 forms lower pole piece 16 andlower rear portion 28 of core 13, as well as lower pole tip 22 and partof via 30. Layer 50 comprises a portion of the CoFeB core of the presentinvention.

Using photolithographic techniques, insulating layer 38 is depositedupon layer 50 of core 13 in the shape shown in FIG. 10. Alumina, Al₂ O₃is deposited in gap 24. Conductors 34 are deposited upon insulatinglayer 38 and formed in a coiled shape.

In FIG. 11, insulating layer 38 has been built up slightly usingphotolithographic masking and etching techniques. Conductors 18 aredeposited similar to conductors 34, and formed in a coiled shape.

In FIG. 12, insulating layer 38 has been built up and covers conductors18 and 34. Next, another layer of magnetic material is deposited overthe structure shown in FIG. 12 to form upper pole piece 14, rear upperportion 26, and a portion of via 30 as shown in FIG. 6. This layer isdeposited using electrodeposition techniques and comprises CoFeB.

Upper pole piece 14 and lower pole piece 16 are deposited upon substrate25 through electroplating. By applying an alternating magnetic fieldduring this electrodeposition step, the anisotropic field H_(k) may bereduced. Alternatively, the core may be annealed in a rotating field tolower the anisotropic field, H_(k). The electroplating bath used in thepresent invention to deposit pole piece 14 and 16 comprises a solutionof cobalt, iron and boron. The addition of boron reduces the coercivityH_(c) of the pole pieces. For thicker films forming upper pole piece 14and lower pole piece 16, this reduction of coercivity H_(c) is evengreater. The addition of boron has little effect on magnetizationsaturation flux density, which remains about 19 K gauss. The addition ofboron along with a rotating magnetic field applied during theelectrodeposition step or the use of rotating magnetic field annealingreduces the coercivity H_(c) and H_(k) of the pole pieces of thin filmhead 12. In a preferred embodiment, the concentration of boron in theelectroplating bath varies from about 0.1% to 2.0% by weight. Ironconcentration may vary from about 7.0% to 12.0% by weight with thebalance of the electroplating bath being cobalt. One suitableelectroplating bath for forming the thin film magnetic read/write headof the present invention is:

                  TABLE 1                                                         ______________________________________                                        Composition       Amount                                                      ______________________________________                                        CoSo.sub.4 7H.sub.2 O                                                                           50-300    grams/liter                                       FeSo.sub.4 H.sub.2 O                                                                            3-15      grams/liter                                       H.sub.3 BO.sub.3  5-50      grams/liter                                       Sodium Saccharin Dihydrate                                                                      0.5-4     grams/liter                                       Dodecyl Sodium Sulfate                                                                          0.1-3     grams/liter                                       DMAB              1-10      drops/liter                                                           of 2 grams/50 m liter                                                         dissolved DMAB                                            Sodium Citrate    0.5-10    grams/liter                                       ______________________________________                                    

DMAB (Dimethyl Amine Borane) acts as a reducing agent and provides thedisassociated boron used for deposition of the CoFeB thin film core. Thedisassociated cobalt ion may range from 5-100 grams/liter in theelectroplating bath. The iron ion may range from 0.2-5.0 grams/liter inthe electroplating bath. Suitable temperature during electroplating isabout 30° C. A suitable pH for the electroplating bath is about 3.5. Theratio between cobalt, iron and boron in the electroplating bath willremain approximately the same in the electroplated film.

Pulse electroplating maybe used during the deposition of the cobalt ironboron core using 6 ampere pulses with a 10 mS on time and a 90 mS offtime. Pulse electroplating helps maintain the magnetic characteristicsof the cobalt iron boron core as the cores thickness grows beyond about0.5 microns, preventing the core from becoming isotropic and losing itshysteresis loop. The thin film exhibits useful magnetic characteristicsfor thickness between about 500 Angstroms and about 10 microns,preferably ranging between about 2000 Angstroms and about 3 microns.

It has been discovered that the anisotropy field H_(k) of the core maybe lowered by two alternative methods. During the electrodeposition ofupper and lower pole pieces 14 and 16, a rotating magnetic field may beapplied. This field should alternate between the normal axis of the coreand 90° off the normal axis. Applying the normal field for 40 seconds ofa one minute cycle and the 90° field for remaining 20 seconds of the oneminute cycle provides a suitable ratio between the two field positions.Alternatively, this rotating field may be applied during an annealingstep in which the core material is subjected to heat.

Table 2 shows a comparison between a nickel iron core (using 82 presentnickel in the alloy), a cobalt iron core (using 90 percent cobalt in thealloy), and the cobalt iron boron core of the present invention (alsousing 90 percent cobalt in the alloy).

                  TABLE 2                                                         ______________________________________                                                Saturation                                                                    Material                                                                      Magnetization                                                         Core    4πMs      Hc        Hk     μ                                    ______________________________________                                        82NiFe  10 KGauss    ˜0.2 Oe                                                                           ˜2.5                                                                         Oe  ˜4000                           90CoFe  19 KGauss    ˜3.0 Oe                                                                           ˜13                                                                          Oe  ˜1500                           90CoFeB 19 KGauss    ˜1.0 Oe                                                                           ˜7                                                                           Oe  ˜2500                           ______________________________________                                    

This table shows that H_(c) and H_(k) are reduced for the CoFeB core ofthe present invention while the value of μ is greatly increased over thecobalt iron core.

Using the cobalt iron boron core of the present invention, the thin filmmagnetic head coercivity H_(c) is reduced over that of a cobalt ironthin film head as the thickness of the film is increased. Using thecobalt iron boron thin film magnetic head of the present invention, thehead will have a high saturation magnetization 4πM_(s), low coercivityH_(c), low anisotropy H_(k) and an increased permeability μ. The thinfilm magnetic read/write head of the present invention offers improvedreading and writing characteristics whereby magnetic storage density maybe increased.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention. For example, different ratios of cobalt,iron and boron may be used in the core and the electroplating bath.

What is claimed is:
 1. A thin film magnetic read/write head comprising:asubstrate; a thin film magnetic core of a metal alloy supported by thesubstrate and including a read/write gap for reading and writinginformation, the metal alloy consisting of cobalt, iron and boron; and acoil magnetically coupled to the magnetic core.
 2. The thin filmmagnetic read/write head of claim 1 wherein the magnetic core compriseslayers of thin film iron alloy, each layer of thin film iron alloyhaving a thickness in a range of about 500 Angstroms to about 10microns.
 3. The thin film magnetic read/write head of claim 1 whereinthe magnetic core contains, by weight percentage, about 0.1% to about2.0% boron, about 7.0% to about 12.0% iron, and a balance of about 86%to about 93% cobalt wherein a total, by weight percentage, or boron,iron and cobalt equals about 100%.
 4. The thin film magnetic read/writehead of claim 1 wherein the magnetic core is deposited throughelectrodeposition techniques.
 5. The thin film magnetic read/write headof claim 4 wherein a rotating magnetic film is applied to the magneticcore during deposition of the magnetic core.
 6. The thin film magneticread/write head of claim 5 wherein the rotating magnetic field rotatesbetween a normal angle and a perpendicular angle about ninety degreesfrom the normal angle.
 7. The thin film magnetic read/write head ofclaim 4 wherein the magnetic core is deposited from an electroplatingbath in which the concentration of boron is between about 0.1% and about2.0% by weight.
 8. The thin film magnetic read/write head of claim 7wherein the electroplating bath contains between about 7.0% and about12.0% iron by weight.
 9. The thin film magnetic read/write head of claim1 wherein the magnetic core is annealed in a rotating magnetic field.10. The thin film magnetic read/write head of claim 9 wherein therotating field rotates between a normal angle and a perpendicular angleabout ninety degrees from the normal angle.
 11. The thin film magneticread/write head of claim 1 wherein the thin film magnetic corecomprises:a separating layer sandwiched between the thin film magneticcore and the substrate; a first magnetic layer having a thickness in arange of about 500 Angstroms to about 10 microns deposited upon theseparating layer; and a second magnetic layer having a thickness in arange of about 500 Angstroms to about 10 microns deposited upon thefirst magnetic layer, wherein the first and the second magnetic layershave a first region at which the first and the second magnetic layersare electrically connected at a via, a second region at which the firstand the second magnetic layers are separated and in which the coil ispositioned, and a third region at which the first and the secondmagnetic layers are separated and form the read/write gap.
 12. The thinfilm magnetic read/write head of claim 11 wherein the read/write gap ofthe third region comprises alumina.
 13. A thin film transducer forreading and writing information to a magnetic storage medium,comprising:a non-magnetic substrate; a first magnetic layer formed of ametal alloy on the non-magnetic substrate, the first magnetic layerincluding a bottom pole tip; a magnetic flux gap layer depositedadjacent to the bottom pole tip and providing a magnetic flux gap; and asecond magnetic layer formed of a metal alloy deposited over themagnetic flux gap layer and including an upper pole tip adjacent to themagnetic flux gap layer, the first magnetic layer and the secondmagnetic layer form a magnetic flux path to edges of the magnetic fluxgap provided by the magnetic flux gap layer, the magnetic flux gapsuitable for magnetically coupling the first magnetic layer and thesecond magnetic layer with the magnetic storage medium, wherein themetal alloy of the first and second magnetic layers includes, by weightpercentage about 86% to about 93% cobalt, about 7% to about 12% iron andabout 0.1% to about 2.0% boron in amounts sufficient to provide asaturation magnetization of 19 K gauss, a coercivity of 1.0 Oersteds, ananisotropy of 7 Oersteds and a permeability of 2500.